Comments on: ESP32-CAM QR Code Reader/Scanner (Arduino IDE)

By: yorrrick

yorrrick — Sat, 26 Jul 2025 18:15:32 +0000

I’m using this library to read QR codes presented by phones when sharing WiFi credentials (ie Tap to share password). It was working fine on Android phones but not on a friend’s iPhone.
I reviewed the original quirc library by dlbeer on github and found that quirc/lib/decode.c contained an additional function void quirc_flip() that is missing from the quirc/decode.c in your library. There was also guidance about how to use it in quirc/lib/quirc.h and specifically that you can flip a QR code if it fails to decode normally and try again. This appears to be necessary for processing QR codes as presented on iPhones. Having added a quirc_flip after getting an initial decode error of type QUIRC_ERROR_DATA_ECC I can now decode my friend’s iPhone QR code. Whether this applies to all iPhones remains to be determined.

By: Sara Santos

Sara Santos — Fri, 11 Jul 2025 09:28:15 +0000

In reply to Joshua Wright.

You can connect the ESP32 to the Arduino via Serial.
This tutorial can help (even though it is for two ESP32): https://randomnerdtutorials.com/esp32-uart-communication-serial-arduino/

Regards,
Sara

By: Joshua Wright

Joshua Wright — Fri, 11 Jul 2025 07:07:33 +0000

I want to use this to send the QR Code data to an arduino mega. I got the ESP32 working but I want it to send what its reading to my Arduino Mega and be able to use that to activate a servo for a project. Any ideas on how to do this?

By: yorrrick

yorrrick — Fri, 20 Jun 2025 12:16:34 +0000

In reply to yorrrick.

Yes – your library is now working on XIAO_ESP32S3 with OV3660 camera
The trick was to add sensor->set_vflip(sensor, 1); in ::setup()

By: yorrrick

yorrrick — Fri, 20 Jun 2025 11:39:20 +0000

In reply to yorrrick.

Yes – your fork is working fine.
The tutorial said you were using the library by Alvarowolfx so I forked that myself. Didn’t realise the link was to a fork of your own in which you’d corrected the error that I was hitting.

My current challenge is to make this work using an OV3660 camera instead of OV2640. I get Decoding Failed: ECC failure, Invalid payload: Format data ECC failure or Error: not a valid qrcode

By: Sara Santos

Sara Santos — Fri, 20 Jun 2025 09:08:49 +0000

In reply to yorrrick.

Hi.
We created a fork of the library to fix the issue.
Is our fork of the library working?
Regards,
Sara

By: yorrrick

yorrrick — Fri, 20 Jun 2025 07:56:46 +0000

In reply to yorrrick. Oh. I see the library you link is not the original alvarowolfx/ESP32QRCodeReader library. You have fixed the error in the original library where .h files were placed in an 'include' folder rather than in 'src'.

By: yorrrick

yorrrick — Fri, 20 Jun 2025 07:35:50 +0000

In reply to yorrrick.

I was able to install this fork of that library: https://github.com/hardwareliberopinerolo/ESP32QRCodeReader

I haven’t explored how they differ but it looks like there is something wrong with the original library when used with Arduino IDE 2.3.2 and 2.3.6

By: yorrrick

yorrrick — Fri, 20 Jun 2025 07:23:32 +0000

In reply to Sara Santos.

I’m getting the same error.

I downloaded the .zip file from GitHub and saved as ESP32QRCodeReader-master.zip
I then used Sketch | Include Library | Add Zip library to add it
Arduino IDE reports: Error: 13 INTERNAL: Library install failed: moving extracted archive to destination dir: library not valid

I’ve looked inside the ZIP and there are a library.json and library.properties that look ok. There’s an include folder and a src folder.
I’m not sure what other validation is done by Arduino IDE
I’m using Arduino IDE 2.3.6 on my desktop and I’ve repeated this with the same results on my laptop using IDE 2.3.2

Not sure what else to check.

By: Sara Santos

Sara Santos — Wed, 11 Jun 2025 09:14:24 +0000

In reply to ezra.

Hi.
It should work with any QR code.
Regards,
Sara